$\dfrac{7}{8} + \dfrac{3}{12} = {?}$
Answer: ${\dfrac{7}{8}}$ ${\dfrac{3}{12}}$ $+$ ${\dfrac{7 \times 3}{8 \times 3}}$ ${\dfrac{3 \times 2}{12 \times 2}}$ $+$ ${\dfrac{21}{24}}$ ${\dfrac{6}{24}}$ $+$ $ = \dfrac{{21} + {6}}{24} $ $ = \dfrac{27}{24}$